This article provides sample Cisco configuration commands for popular cities using “clock timezone” and “clock summer-time” commands. It also aggregates information about different time zones and their daylight saving dates.
Many services are dependent on the clock and time zone configuration on Cisco devices. Services such as certificate validity checks, logging are the obvious ones. The other examples include time-based ACLs or scheduled tasks that can cause outages during the daylight saving changes. The daylight savings rules are also changing time after time.
Time Zones and Daylight Settings
The time zone represents an area or region that observes the same time. Coordinated Universal Time (UTC) is the reference time. Time zones are expressed as an offset from it. Offset can be either negative or positive represented in a number of hours and in some cases in minutes.
Some regions observe daylight savings time when clocks are adjusted twice a year so there is an extra hour of daylight in the evening during summer. There are more daylight hours in summer than during winter. The difference is more noticeable when moving away from the equator. The adjustment is done in spring by moving clocks forward (spring forward) and then reversed in autumn by moving clocks back (fall back). Note that summer starts in December in some of the countries in the Southern hemisphere.
Time Configuration on Cisco devices
We recommend using NTP to ensure that time is accurately synchronized. NTP server sends time information in UTC, so it is important to set the correct time zone.
If manual clock settings are in use, the router assumes that the time is specified in the router’s local time zone, which is UTC by default. Therefore, the time zone settings should be configured before setting the clock manually, as otherwise, it will need to be re-adjusted after the router applies time zone configuration.
The following paragraphs show how to configure the correct time zone and daylight savings settings on the device.
To specify time zone and daylight settings two commands are used:
R1(config)#clock ? summer-time Configure summer (daylight savings) time timezone Configure time zone
Time zone configuration requires only 2 parameters:
clock timezone zone hours-offset [minutes-offset]
Summer-time configuration can be either recurring or date-specific:
clock summer-time zone recurring [week day month hh:mm week day month hh:mm [offset]] clock summer-time zone date date month year hh:mm date month year hh:mm [offset]
Time Configuration on Cisco devices
The easiest way to lookup information is by navigating to the timeanddate.com website and browsing to the world clock page.
Then find the city name and click on it. Select the Time Zone button and it will display abbreviation and up-to-date information on when DST starts.
Below are the configuration samples for some of the popular cities with updated daylight information as of March 2020.
North America
| City | Command |
|---|---|
| Honolulu, US | # Hawaii Standard Time clock timezone HST -10 |
| Vancouver, Canada | # Pacific Standard Time clock timezone PST -8 # Pacific Daylight Time clock summer-time PDT recurring 2 Sun Mar 2:00 1 Sun Nov 2:00 |
| Los Angeles, US San Francisco, US Las Vegas, US Seattle, US | # Pacific Standard Time clock timezone PST -8 # Pacific Daylight Time clock summer-time PDT recurring 2 Sun Mar 2:00 1 Sun Nov 2:00 |
| Mexico City, Mexico | # Central Standard Time clock timezone CST -6 # Central Daylight Time clock summer-time CDT recurring 1 Sun Apr 2:00 last Sun Oct 2:00 |
| Denver, US | # Mountain Standard Time clock timezone MST -7 # Mountain Daylight Time clock summer-time MDT recurring 2 Sun Mar 2:00 1 Sun Nov 2:00 |
| Cancun, Mexico | # Eastern Standard Time clock timezone EST -5 |
| Panama, Panama | # Eastern Standard Time clock timezone EST -5 |
| New Orleans, US Kansas City, US Austin, US Dallas, US Milwaukee, US | # Central Standard Time clock timezone CST -6 # Central Daylight Time clock summer-time CDT recurring 2 Sun Mar 2:00 1 Sun Nov 2:00 |
| Ottawa, Canada Ontario, Canada Montreal, Canada Quebec, Canada | # Eastern Standard Time clock timezone EST -5 # Eastern Daylight Time clock summer-time EDT recurring 2 Sun Mar 2:00 1 Sun Nov 2:00 |
| Havana, Cuba | # Cuba Standard Time clock timezone CST -5 # Cuba Daylight Time clock summer-time CDT recurring 2 Sun Mar 2:00 1 Sun Nov 1:00 |
| Washington DC, US Florida, US Tampa, US Atlanta, US Indianapolis, US Louisville, US Baltimore, US Boston, US Michigan, US New York, US Philadelphia, US Pittsburgh, US Portsmouth, US | # Eastern Standard Time clock timezone EST -5 # Eastern Daylight Time clock summer-time EDT recurring 2 Sun Mar 2:00 1 Sun Nov 2:00 |
| Halifax, Canada | # Atlantic Standard Time clock timezone AST -4 # Atlantic Daylight Time clock summer-time ADT recurring 2 Sun Mar 2:00 1 Sun Nov 2:00 |
Table 1. North America Cities and Cisco Timezone Configuration Commands
South America
| City | Command |
|---|---|
| Bogota, Colombia | # Colombia Time clock timezone COT -5 |
| Lima, Peru | # Peru Time clock timezone PET -5 |
| Santa Cruz, Bolivia | # Bolivia Time clock timezone BOT -4 |
| Caracas, Venezuela | # Venezuelan Standard Time clock timezone VET -4 |
| Buenos Aires, Argentina Santa Fe, Argentina | # Argentina Time clock timezone ART -3 |
| Brasilia, Brazil Rio de Janeiro, Brazil Sao Paulo, Brazil | # Brasilia Time clock timezone BRT -3 |
| Asuncion, Paraguay | # Paraguay Time clock timezone PYT -4 # Paraguay Summer Time clock summer-time PYST recurring 1 Sun Oct 0:00 last Sun Oct 0:00 |
| Montevideo, Uruguay | # Uruguay Time clock timezone UYT -3 |
Table 2. South America Cities and Cisco Timezone Configuration Commands
Europe
| City | Command |
|---|---|
| Reykjavik, Iceland | # Greenwich Mean Time clock timezone GMT |
| Dublin, Ireland | # Greenwich Mean Time clock timezone GMT # Irish Standard Time (Daylight saving) clock summer-time IST recurring last Sun Mar 1:00 last Sun Oct 2:00 |
| Lisbon, Portugal Porto, Portugal | # Western European Time clock timezone WET # Western European Summer Time clock summer-time WEST recurring last Sun Mar 1:00 last Sun Oct 2:00 |
| Birmingham, UK Bristol, UK Leeds, UK Liverpool, UK London, UK Manchester, UK Belfast, UK Edinburgh, UK Glasgow, UK | # Greenwich Mean Time clock timezone GMT # British Summer Time clock summer-time BST recurring last Sun Mar 1:00 last Sun Oct 2:00 |
| Tirana, Albania Salzburg, Austria Vienna, Austria Brussels, Belgium Sarajevo, Bosnia-Herzegovina Zagreb, Croatia Prague, Czechia Copenhagen, Denmark Strasbourg, France Paris, France Versailles, France Toulouse, France Marseille, France Stuttgart, Germany Munich, Germany Berlin, Germany Hamburg, Germany Frankfurt, Germany Hannover, Germany Dortmund, Germany Leipzig, Germany Gibraltar, Gibraltar Budapest, Hungary Naples, Italy Turin, Italy Venice, Italy Amsterdam, Netherlands The Hague, Netherlands Oslo, Norway Krakow, Poland Warsaw, Poland Belgrade, Serbia Ljubljana, Slovenia Barcelona, Spain Ibiza, Spain Madrid, Spain Stockholm, Sweden Bern, Switzerland Geneva, Switzerland Lugano, Switzerland Vatican City, Vatican City State | # Central European Time clock timezone CET +1 # Central European Summer Time clock summer-time CEST recurring last Sun Mar 2:00 last Sun Oct 3:00 |
| Plovdiv, Bulgaria Sofia, Bulgaria Tallinn, Estonia Helsinki, Finland Athens, Greece Riga, Latvia Vilnius, Lithuania Bucharest, Romania Kyiv, Ukraine Odesa, Ukraine | # Eastern European Time clock timezone EET +2 # Eastern European Summer Time clock summer-time EEST recurring last Sun Mar 3:00 last Sun Oct 4:00 |
| Kaliningrad, Russia | # Eastern European Time clock timezone EET +2 |
| Minsk, Belarus Bryansk, Russia Sochi, Russia Moscow, Russia Saint-Petersburg, Russia | # Moscow Standard Time clock timezone MSK +3 |
Table 3. Europe Cities and Cisco Timezone Configuration Commands
Asia
| City | Command |
|---|---|
| Jerusalem, Israel Tel Aviv, Israel | # Israel Standard Time clock timezone IST +2 # Israel Daylight Time clock summer-time IDT recurring last Sun Mar 2:00 last Sun Oct 2:00 |
| Beirut, Lebanon | # Eastern European Time clock timezone EET +2 # Eastern European Summer Time clock summer-time EEST recurring last Sun Mar 0:00 last Sun Oct 0:00 |
| Baghdad, Iraq Kuwait City, Kuwait Doha, Qatar Riyadh, Saudi Arabia | # Arabia Standard Time clock timezone AST +3 |
| Istanbul, Turkey | # Turkey Time clock timezone TRT +3 |
| Tbilisi, Georgia | # Georgia Standard Time clock timezone GET +4 |
| Yerevan, Armenia | # Armenia Time clock timezone AMT +4 |
| Baku, Azerbaijan | # Azerbaijan Time clock timezone AZT +4 |
| Dubai, United Arab Emirates | # Gulf Standard Time clock timezone GST +4 |
| Kabul, Afghanistan | # Afghanistan Time clock timezone AFT +4 30 |
| Tehran, Iran | # Iran Standard Time clock timezone IRST +3 30 # Iran Daylight Time 2020 clock summer-time IRDT date 21 Mar 2020 0:00 21 Sep 2020 0:00 # Iran Daylight Time 2021-2023 clock summer-time IRDT date 22 Mar 2021 0:00 22 Sep 2021 0:00 clock summer-time IRDT date 22 Mar 2022 0:00 22 Sep 2022 0:00 clock summer-time IRDT date 22 Mar 2023 0:00 22 Sep 2023 0:00 |
| Islamabad, Pakistan Karachi, Pakistan Lahore, Pakistan | # Pakistan Standard Time clock timezone PKT +5 |
| Ufa, Russia Chelyabinsk, Russia Yekaterinburg, Russia | # Yekaterinburg Time clock timezone YEKT +5 |
| Dushanbe, Tajikistan | # Tajikistan Time clock timezone TJT +5 |
| Ashgabat, Turkmenistan | # Turkmenistan Time clock timezone TMT +5 |
| Tashkent, Uzbekistan | # Uzbekistan Time clock timezone UZT +5 |
| Delhi, India New Delhi, India Bangalore, India Mumbai, India Kolkata, India Colombo, Sri Lanka | # India Standard Time clock timezone IST +5 30 |
| Kathmandu, Nepal | # Nepal Time clock timezone NPT +5 45 |
| Dhaka, Bangladesh | # Bangladesh Standard Time clock timezone BST +6 |
| Almaty, Kazakhstan Nursultan, Kazakhstan | # Alma-Ata Time clock timezone ALMT +6 |
| Bishkek, Kyrgyzstan | # Kyrgyzstan Time clock timezone KGT +6 |
| Omsk, Russia | # Omsk Standard Time clock timezone OMST +6 |
| Phnom Penh, Cambodia Hanoi, Vietnam Ho Chi Minh, Vietnam | # Indochina Time clock timezone ICT +7 |
| Jakarta, Indonesia | # Western Indonesian Time clock timezone WIB +7 |
| Novosibirsk, Russia | # Novosibirsk Time clock timezone NOVT +7 |
| Beijing, China Guangzhou, China Shenzhen, China Harbin, China Nanjing, China Shanghai, China Chengdu, China Lhasa, China Hangzhou, China Taipei, Taiwan | # China Standard Time clock timezone CST +8 |
| Hong Kong, Hong Kong | # Hong Kong Time clock timezone HKT +8 |
| Kuala Lumpur, Malaysia | # Malaysia Time clock timezone MYT +8 |
| Manila, Philippines | # Philippine Time clock timezone PHST +8 |
| Irkutsk, Russia | # Irkutsk Time clock timezone IRKT +8 |
| Singapore, Singapore | # Singapore Time clock timezone SGT +8 |
| Kyoto, Japan Osaka, Japan Sapporo, Japan Tokyo, Japan Yokohama, Japan | # Japan Standard Time clock timezone JST +9 |
| Chita, Russia Yakutsk, Russia | # Yakutsk Time clock timezone YAKT +9 |
| Busan, South Korea Daegu, South Korea Incheon, South Korea Seoul, South Korea | # Korea Standard Time clock timezone KST +9 |
| Vladivostok, Russia | # Vladivostok Time clock timezone VLAT +10 |
Table 4. Asia Cities and Cisco Timezone Configuration Commands
Africa
| City | Command |
|---|---|
| Bissau, Guinea-Bissau Monrovia, Liberia Timbuktu, Mali Dakar, Senegal | # Greenwich Mean Time clock timezone GMT |
| Algiers, Algeria Constantine, Algeria Tunis, Tunisia | # Central European Time clock timezone CET +1 |
| Kinshasa, Congo Lagos, Nigeria | # West Africa Time clock timezone WAT +1 |
| Casablanca, Morocco Marrakech, Morocco Tangier, Morocco | # Western European Summer Time clock timezone WEST +1 |
| Alexandria, Egypt Cairo, Egypt Tobruk, Libya Tripoli, Libya | # Eastern European Time clock timezone EET +2 |
| Cape Town, South Africa Johannesburg, South Africa Pretoria, South Africa | # South Africa Standard Time clock timezone SAST +2 |
| Khartoum, Sudan Port Sudan, Sudan | # Central Africa Time clock timezone CAT +2 |
| Addis Ababa, Ethiopia Mombasa, Kenya Mogadishu, Somalia Zanzibar City, Tanzania | # Eastern Africa Time clock timezone EAT +3 |
Table 5. Africa Cities and Cisco Timezone Configuration Commands
Australia/Pacific
| City | Command |
|---|---|
| Perth, Australia | # Australian Western Standard Time clock timezone AWST +8 |
| Darwin, Australia | # Australian Central Standard Time clock timezone ACST +9 30 |
| Brisbane, Australia Cairns, Australia | # Australian Eastern Standard Time clock timezone AEST +10 |
| Adelaide, Australia | # Australian Central Standard Time clock timezone ACST +9 30 # Australian Central Daylight Time clock summer-time ACDT recurring 1 Sun Oct 2:00 1 Sun Apr 3:00 |
| Canberra, Australia Sydney, Australia Hobart, Australia Melbourne, Australia | # Australian Eastern Standard Time clock timezone AEST +10 # Australian Eastern Daylight Time clock summer-time AEDT recurring 1 Sun Oct 2:00 1 Sun Apr 3:00 |
| Noumea, New Caledonia | # New Caledonia Time clock timezone NCT +11 |
| Port Vila, Vanuatu | # Vanuatu Time clock timezone VUT +11 |
| Auckland, New Zealand Christchurch, New Zealand Wellington, New Zealand | # New Zealand Standard Time clock timezone NZST +12 # New Zealand Daylight Time clock summer-time NZDT recurring last Sun Sep 2:00 1 Sun Apr 3:00 |
Table 6. Australia/Pacific Cities and Cisco Timezone Configuration Commands
Reference Information
Alphabetically sorted list of time zone abbreviations:
https://www.timeanddate.com/time/zones/
IANA supports the time zone database (https://www.iana.org/time-zones) and at the time of this blog post writing the latest one is 2019c release. To receive updates on time zone database updates, you can subscribe to the IANA’s mailing list (https://mm.icann.org/mailman/listinfo/tz-announce).